Certain mechanical systems include one or more actuators to provide a desired linear or rotary motion to a moveable element. Such actuators include a motor and output drive train and typically include position sensors to measure the position of the moveable elements in the mechanical system.
For example, conventional aircraft utilize one or more actuators to adjust and maintain the position of aircraft flight control surfaces such as ailerons, elevators, and rudders. In order to track the relative position of the aircraft flight control surfaces, the actuators include one or more linear position sensors, such as a linear variable differential transformer (LVDT). Conventional LVDTs include a primary coil of wire and two secondary coils of wire that surround a ferromagnetic core. During operation, as the actuator adjusts the position of a corresponding flight control surface, the actuator also adjusts the position of the ferromagnetic core relative to the coils of wire. As the ferromagnetic core translates past the primary and secondary coils, the ferromagnetic core causes the voltages induced in the secondary coils to change. The change in the induced voltage corresponds to the change in linear position of the ferromagnetic core and the change in position of corresponding flight control surface. Accordingly, as the LVDT provides an output signal, corresponding to the induced change in voltage, to an actuator controller, the actuator controller can detect the exact position of the flight control surface.